Question will a 124 CCU from an 86-87 moddel swap in for a 123 300td 1981 version....

they look the same will they work the same?

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81 300td turbo 212,000

It would all depend on the electrical pin outs and connectors.

Are the part numbers the same?

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Im looking at buying it off ebay... and well the person says it does not havwe the Part # on it anywhwere... so dont know?

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81 300td turbo 212,000

Part number on you old unit and for the new one would be key. The EPC might have it. IF the one in your car had it's part number superceded, that should be noted as well

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

what is the EPC and would the benz dealer know if it has been superceded?

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81 300td turbo 212,000

IIRC it stands for Electronic Parts Catalog. It was a free down load, but I clicked a link posted on this forum a few months ago.

The MB dealer may or may not know. Some are helpful, some are not. They should know the part number to the climate control head units.

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

CCU on an '81 300TD is 123 830 12 85.

CCU on an '86 300SDL is 126 830 05 85.

CCU on an '86 300E is 124 830 33 85 88.

The connection pins for the 124 and 126 CCU's (14 pins on the bottom each side) are different than for the 123's (12 pins on each side of unit).

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too many w123's
84 280 SL 5 speed

Looks like the cut off year would be either '84 or '85. The CCU from an '85 w126 should work in a w123, as I recall. I could be wrong though.

Thanks dadette!

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Nope, you're right about the CCU from an '85 W126 working. Same pin configuration (even though slightly different part number, 126 830 02 85).

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too many w123's
84 280 SL 5 speed

The climate control system in the 86+ cars is totally different. (and borrowed from the W124 for the W126)

-Jason

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Do you happen to know if one from a late 80s or 90-91 126 gasser would plug directly into a SDL? I have one of each; mine is fritzing out and I need to replace it with one of two junkyard options. The one out of the diesel is almost as worn looking on the face as mine. The one from the 420SEL is in pristine condition. Looks like the same pins and plugs, but I have no idea if they do the same function or not.

The part number is difficult because IIRC they printed it on the front face and then stapled the wood grain on over it. If you separate the two to read the number, you have the new problem of reattaching the CCU to the wood face.

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~Michael S.~
Past cars:

1986 300SDL
1987 300SDL
1982 240D
1982 300SD


Current:

1987 300SDL

I recall someone saying that the diesels got a different control unit then the gassers. I'd have to look at the wiring diagrams to see what the differences, if any, are.

-Jason

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.